The present invention is directed to communication systems.
Over the last few decades, the use of communication networks exploded. In the early days of the Internet, popular applications were limited to emails, bulletin board, and mostly informational and text-based web page surfing, and the amount of data transferred was usually relatively small. Today, Internet and mobile applications demand a huge amount of bandwidth for transferring photo, video, music, and other multimedia files. For example, a social network like Facebook processes more than 500 TB of data daily. With such high demands on data and data transfer, existing data communication systems need to be improved to address these needs. For high-speed data communication applications, pulse-amplitude modulation (PAM) technique is often used. Among other things, PAM (2n, with n>1) provides an improved spectral efficiency that allows for higher data throughput on communication media.
Over the past, there have been many types of communication systems and methods. Unfortunately, they have been inadequate for various applications. Therefore, improved systems and methods are desired.